1. Field of the Invention
This invention relates to an integrated circuit technique for producing an accurate high-speed analog comparator with low power consumption.
2. Description of the Prior Art
An analog comparator is a basic functional unit utilized in analog circuit design, as, for example, in analog-to-digital converters (ADCs). The relative performance of analog comparators is measured by their specifications, such as input offset voltage, offset current, propagation delay, skew, power consumption, etc. In some applications, the input offset voltage and offset current specification can be relaxed (traded off) when other performance criteria are critical. For example, in optical and digital data receivers or in high speed medium resolution ADCs having embedded analog comparators, e.g., those used in video applications (eight or nine bit resolution with ten megahertz conversion rates), low propagation delay through the analog comparators is the most important criteria. Alternatively, in low speed medium resolution ADCs having embedded analog comparators, e.g., ADCs used in telephone (voice) applications where many thousands thereof are employed in channel banks and line cards of switching systems (eight to twelve bits resolution, eight kilohertz conversion rates), the power consumption of the analog comparators is of primary importance. Hence, it is desirable to have a single analog comparator design easily adaptable for any application.